Compare headers in a case insensitive way
Compare headers in a case insensitive way

HTTP headers are case insensitive (http://www.w3.org/Protocols/rfc2616/rfc2616-sec4.html#sec4.2). This change converts the input headers and the schema headers to lowercase before comparing them with the Validator.

inetsys/SwaggerAssertions,Beanhunter/SwaggerAssertions